media: verisilicon: Add film grain feature to AV1 driver

Film grain feature add "old style" grain noise on decoded streams.
Grain noise is applied after decoding by the postprocessor.
The level of grain is based on gaussian sequence.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
Reviewed-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: verisilicon: Add Rockchip AV1 decoder

Implement AV1 stateless decoder for rockchip VPU981.
It decode 8 and 10 bits AV1 bitstreams.
AV1 scaling feature is done by the postprocessor.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
Reviewed-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>